Door operating mechanism



June 12, 1962 H. G. RIGBY DOOR OPERATING MECHANISM 2 Sheets-Sheet 1Filed Dec. l5, 1959 June 12, 1962 H. G. RIGBY DOOR OPERATING MECHANISM 2Sheets-Sheet 2 Filed Deo. l5, 1959 Nw @Y Harvey G. .ZErLyZy INVENTOR.

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Arm/@Ney United States Patent O 3,038,536 DOOR OPERATING MECHANISMHarvey G. Rigby, 2223 Duncan Ave., Cornwells Heights, Pa. Filed Dec. 15,1959, Ser. No. 859,725 1 Claim. (Cl. 160-193) This invention relates tomechanisms for opening and closing hingedly sectional doors of the typehaving an endless chain connected to the door and driven by an electricmotor for alternately moving the door from a vertical closed position toa horizontal overhead open position, and reversing its movement to itsclosed position. Such doors for garages or other buildings are usuallyprovided with rollers at their edges mounted in right angular channeltracks or guides supported in the building on opposite sides of the dooropening for guiding the door in its opening and closing movements. Thevertical and horizontal portions of the tracks are joined by a curvedportion to facilitate the travel of the door from one position to theother.

`One of the principal objects of my invention is to provide a mechanismfor opening and closing a door of the character mentioned of moresimplified and economical construction than previous mechanisms of thetype referred to and which will be more eicient and reliable inoperation, and also in which the individual parts of the mechanism caneasily be replaced.

`In my improved door operating mechanism I employ only a single chainfor operating the door lift, thus dis.- pensing with belts and pulleys,ropes and chains used in previous mechanisms; and the opening andclosing movements of the door are controlled by a single electrical pushbutton. Any desired number of such buttons connected in the electricalcircuit with the motor may be installed in various convenient locations.The motor may also be operated from a vehicle or other remote locationby means of a radio control.

Another important object of this invention is to provide a mechanism ofthe character mentioned with convenient and effective means fordisconnecting the motor from the chain drive in the event of a powerfailure.

A further object of the invention is to provide automatic means fordisconnectingy the chain drive from the motor in the event of the doorbecoming stuck, wedged or frozen to the iloor or frame of the building,thereby eliminating any danger of breaking the mechanism or damaging thedoor.

A still further important feature of my improved door operatingmechanism resides in the construction whereby the worm gear whichconnects the motor with the chain drive is supported solely by two ballbearings in the gear housing, so that a two-section chain sprocketoperating shaft which extends through an axial bore in the worm gear isentirely free from any strain which might otherwise be imparted byrotation of the gear. In the construction referred to, both sections ofthe shaft can be entirely withdrawn from the worm gear, leaving itundisturbed in its bearings.

Other objects and advantages of my invention will appear or be pointedout in the following specification in Which reference is directed to theaccompanying drawings forming a part thereof, and in which:

FIG. l is a sectional view through the central portion of a door of thecharacter mentioned with my improved door operating mechanism connectedthereto;

FIG. 2 is a detail side elevation of my improved roller carrierconnection from the operating chain to the door;

FIG. 3 is a section taken on the line 3 3 of FIG. 2;

FIG. 4 is a diagram showing the electrical connections from the dooroperating chain to the motor;

FIG. 5 is a frontal view of a two-point switch actu ated by the dooroperating chain;

FIG. 6 is a -section through the worm gear housing taken on the line 6-6of FIG. l;

FIG. 7 is a detail top plan, partly in section showing the frontsprocket adjacent the door `and roller carrier track;

FIG. 8 is a side elevation of the parts shown in FIG. 7;

FIG. 9 is an end view of the coupling end of one section of thetwo-section chain operaitng shaft; and

FIG. l0 is a detail View showing a cushioning device between the doorlift connection, or draw bar, and the door.

Referring to the drawings in which like numerals designate like pants inthe several views 10' designates a garage or other building having afront wall 12 (FIG. l) provided with a door opening 14. Right angularchannel tracks 16, having curved portions 18 joining their vertical andhorizontal portions, `are mounted on the Wall 12 on opposite sides ofthe opening 14. A door 20 consisting of horizontal hinged sections isfreely mounted against the rear of the opening 14 and has rollers 22 atits edges in the channel tracks for guiding the door in its opening andclosing movements. The door 20 may be held under lifting tension bymeans of elongated springs 24 connected to the bottom of the door ateach edge through cables 26 -mounted on stationary pulleys 28, journaledin brackets 17 through which the tracks 16 are attached to the wall 12,and a floating pulley 30, for reducing the force required by theoperating mechanism, hereinafter to be described, in opening the door.

My improved door operating mechanism includes a worm gear housing 32(FIGS. 1-5) having an upwardly facing base portion 34 for attachmentthrough hangers 36 to `a joist 38 (FIG. l) or other support in thebuilding 1t). Operating shaft housings 40 and 42 extend horizontallyfrom each side of the housing 32, and a twosection shaft comprisingsections 44 and 46 is journaled in these housings. Shaft section 44 isjournaled in ball bearings 48 in housing 40 and has a reduced portion 50projecting therefrom, forming a shoulder 52 immediately outside thesurface of the housing for a purpose hereinafter explained. 'Ihe section44 has a coupling slot or recess 56 in its inner end (FIG. 9) and athrust flange or collar 58 a short distance back from this end `andabutting the adjacent ball bearing 48. Shaft s'ection 46 is journaled inplain bearings 60 and 62 in housing 42, this shaft having on its innerend a at or rectilin-ear key portion 64 coengageable with the recess 56in section 44 lfor coupling the two sections together. Section 46 isaxially shiftable toward and from section 44 by means of a lever 66connected through ball bearing 68 to the outer end of the section and inengagement at its upper end with the wor-m gear housing 32. A detent 70in the bearing 60 is designed to hold the section 46 into or out ofcoupling engagement with section 44. A worm gear 72 has oppositelyprojecting hubs 74 which are journaled in ball bearings 76 in theopposed inner ends of the housings 40 and 42. This worm gear has anaxial bore 78 through which the two-section shaft loosely extends. Thehub 74 in housing 40 abuts the thrust llange 58 on the opposite sidefrom that abutting the ball bearing 48 to hold shaft section 44 againstaxial movement. The bore 78 being of slightly greater diameter thanshaft sections 44 and 46 permits free movement of the sections therein,the worm gear being supported solely by the ball bearings 76independently of the shaft sections, so that no strain is exerted on theshaft sections by the Worm gear. A key 80 (shown in broken lines inyFIG. 6) in opposed slots in shaft `section 42 and the bore 78 of theworm gear renders that shaft section axially shiftable toward and fromlshaft lsection 44, but non-rotatable in said worm gear.

A worm shaft 82 is journaled in the housing 32 at right angles to shaftsections 44 and 46 and a worm 84 is mounted on the shaft in engagementwith the worm gear 72. An electric motor 86 is coupled (by means notshown) to the worm shaft 82 for driving said shaft, and the motor 86`may be mounted on the housing 32 (as indicated in FIG. 1).

A sprocket 88 is rotatably mounted on the reduced portion 50 of shaft44. Also loosely mounted on said reduced portion on opposite sides ofsprocket 88 are friction drive disks 90. The supporting inner face plate92 is pinned or otherwise fixedly mounted on the reduced portion 50adjacent the shoulder 52 on shaft 44, the. supporting outer face plate92 being loosely mounted on the reduced portion l50 of the shaft 44. Theouter end of reduced portion 50 is threaded and provided outwardly ofthe pressure plate Y916 with an adjustable nut 98. A helical spring 100is interposed between pressure plate 98 and opposed face plate 92,thisspring urging the `loosely mounted members `of the assembly towardVthe iixedly mounted inner face plate 92. It should here be pointed outthat the shaft 44 may be of uniform ldiameter with a fixed collar 94serving in place of the shoulder 52. Another sprocket 102 is mountedbetween supports '104 on the Wall 12 in alignment with sprocket 88. Anendless chain 106 is mounted on the two sprockets. The sprocket 102 maybe journaled in longitudinally adjustable bearings 105 on the supports104, and provided with screws 108 or other suitable means for adjustingthe tightness of the chain. Forming a link in the chain 106 is a carrier110 having rollers 112 mounted on an'inverted T-shaped track 114attached at its front end to the supports 104 and at its other end to arelay housing 115, mounted on the Worm gear housing 32, or othersuitable support, so that the track is aligned between the twosprockets. A strip 116 of wood or other non-metallic material is mountedon top of the track for supporting the chain, which is attached todepending'lugs 118 and 120 on the carrier 110. A draw -bar V122 ispivotally connected to one end of lug 118 land at its other end to aspring cushion assembly 124 comprising top and bottom cross bars 126rigidly mounted on rods 128 and an intermediate bar 130 slidably mountedon said bars and having helical springs 132 interposed between it andthe top bar. The bottom bar is rigidly attached at 133 to the top of thedoor 20. The door lift or draw -bar 122 projects slidably through anopening in the top bar and is rigidly attached to the intermediate bar130, so that a pull on the draw bar will be cushioned by the springs132.

Oppositely facing, one-way switch actuating dogs 134 are attached to theendless chain 106 for the actuation of a two-point electrical limitswitch 136 pivotally mounted on the relay housing 115. This switch isfor the purpose of stopping the motor 86 at the end of the travel of thechain in each direction when the door 20 arrives at open or closedposition. Accordingly the dogs 134 are spaced apart longitudinally ofthe chain the correct distance to bring the door from its closed to itsoverhead open position. The dogs 134 are pivotally mounted on andbetween depending portions of special links 138 of the same length asthe links of the chain 106 (FIG. in which they are connected, so thattheir 1ocation in the chain can be varied to accommodate doors ofdifferent lengths, or heights. Each dog is provided in its front endwith a recess in which a depending switch actuating lug 140l ispivotally mounted in a manner to permit only forward pivotal movement.The limit switch 136 has two upwardly diverging arms 142 and, as shownin FIG. 5, one of the arms has been moved to its limit position by thelug 140. As alsor shown in broken lines in FIG. 5, the lug 1-40 willfold and ride idly over the other arm when moved in a reverse direction,leaving that arm to be actuated by the other dog on the chain. Thepositions of the arms 142 as shown in FIGS. l and 5, and also in theelectrical diagram FIG. 4, are those immediately following the movementofthe door to its down or closed position. The limit switch has twocontacts 144 and 146 and is connected at 148 with a transformer 150i. Asshown in FIGS. 4 and 5, the limit switch includes a single depending arm143 disposed between and designed for alternate engagement with contacts144 and 146. Contacts 144 and 146 are connected through a sequence relay152, mounted in the relay box 115, with the reversing coils 154 and 156(FIG. 4) of the motor 86. The switch 136 is on contact 144 but the relayswitch is fopen and will not be closed until actuated by a push-buttonswitch 158 connected in the circuit with the relay. The motor relay andpush button switch may be of conventional types but the combinationofthe limit switch 136 and the actuating dogs 134 is of specialconstruction for control of the motor and chain operation. 'Push buttonswitches 158 (shown only schematically in FIG. 4) of the single 'plungertype are preferably used in connection with the relay 152.

As already mentioned, the door with its operating instrumentalities isshown in FIG. l as immediately after having been moved to its closedposition. To open the door it is necessary to actuate one of the pushbutton switches 158 which will close the open switch of the relay 152thus activating reversing coil 156 of the motor 86, which will thenrotate until the other dog actuates the upright arm 142 of the limitswitch 136, thereby activating the relay and breaking the connectionwith reversing coil 156, which immediately stops the motor and theopening movement of the door, also setting the yrelay switch in positionfor the closing movement of the door'upon actuation of either one ofpush button switches 158, Wherever located. Also instead of push buttonswitches, a radio relay 160 may be operated from a motor vehicle orother location.

If, in the opening or closing movement of the door, it should becomestuck for any reason the friction clutch disks will permit free rotationof the reduced shaft portion 50 of the shaft section 44 while thesprocket remains stationary, thereby preventing breakage of parts of themechanism or damage to the door. The. clamping force of the disks 90against the sides of the sprocket may be adjusted by means of the nut 98on `the end of the reduced section. The shaft sections 44 and 46 mayalso be instantly uncoupled Vb-y means of the lever 66.

From the foregoing description it will be seen that my friction driveassembly is of a fixed nature. To adjust the torque of the assembly thenut 98 is tightened to exert barely enough torque to lift the door 20.If the door should -be jammed, frozen by ice or by snow in the sprocket88, the shaft will rotate through the sprocket 88 and not damage thedoor. To start the door in motion it is necessary only to press any oneof the push buttons 158, which can be installed in various locations. Ifthe door is stuck, frozen or jammed, or the power fails the twooperating shafts 44 and 46 can be disengaged by pulling the lever 66,after which the whole assembly will float freely, and can be manuallyoperated in a normal manner. To start the assembly in motion again thelever 66 is pushed in to engage the shafts 44 and 46. When the door isin motion, say on an opening cycle, it can be stopped in travel`anywhere in that cycle, but cannot be reversed until it has reached itsfull travel. The same applies on the closing cycle. When the door isfully closed it is locked and cannot be pried open from outside orinside.

Obviously, various modifications or changes may be made in my improveddoor operating mechanism. without `departing from the spirit and scopeof my invention. Therefore, it should be understood that the embodimentof my invention shown and described is intended to be illustrative,only, and restricted only by the appended claim.

I claim:

In a mechanism for operating a hingedly sectional overhead opening doorincluding a horizontal endless chain having its front end connected tosaid door and mounted on a sprocket supported above said door, saidchain being mounted `at its rear end on another sprocket carried by ashaft journaled in a housing and geared to a reversible electric motorhaving its respective reversing coils connected in an electrical circuitwith a relay; a twopoint electrical switch mounted on a support belowthe 1rear end of said chain and connected in said electrical circuit,said switch having a pair of horizontally spaced contacts connectedthrough said relay with the reversing coils of said motor, said switchalso having a rotatable member comprising a pair of horizontally spaced,upwardly projecting arms and a single depending contact arm, the latterbeing disposed between said pair of contacts for alternate engagementtherewith; and a pair of 20 horizontally spaced depending and oppositelyfacing one- Way switch actuating dogs on said chain for alternatelyabutting and overriding engagement with the inner edges of said upwardlyprojecting arms for alternately shifting said Contact arm from one ofsaid contacts to the other; said chain shaft being in two disengageablesections extending through an axial bore in a worm gear rotatablyconnected to the motor through a worrn on the motor shaft, the forwardsection of the shaft on which the sprocket is mounted being vrotatablebut axially stationary and the rearward section being keyed to butaxially shiftable within the bore of the worm gear and provided withmeans for axially shifting it into and out of engagement with theforward section of the shaft, said worm wheel having axially projectinghub portions journaled in bearings in the shaft housing independently ofthe bearings of the two shaft sections.

References Cited in the le of this patent UNITED STATES PATENTS1,649,797 Winn Nov. 15, 1927 2,099,191 Blodgett NOV. 16, 1937 2,163,514Farren June 20, 1939 2,262,719 Collins Nov. 11, 1941 2,589,480 CurtisMar. 18, 1952 2,850,088 Purdy Sept. 2, 1958

